Ranges

The key difference between Ranges and a simple Bitmap Mask is that selection is not driven by a single Low/High threshold. Blackmagic describes Ranges as a spline-based selection of low, mid and high ranges, similar to the Ranges controls in Color Corrector. This gives independent control over where shadows and highlights begin/end and how their Bezier falloff behaves.

Ranges is a mask tool. The orange Image input accepts the 2D image whose values are analyzed, while the output is a single-channel mask. Source RGB does not pass through Ranges as a normal image stream, so a plate being graded or blurred must travel separately to ColorCorrector/Blur/Glow while Ranges.Mask goes to the target Effect Mask.

The node also has an optional blue Effect Mask input. It does not replace Image: it is a separate mask branch used to spatially limit or combine with the tonal matte generated by Ranges. When this input is connected, Paint Mode appears in the Inspector and defines how the incoming mask and the Ranges matte are combined.

The Shadows, Midtones and Highlights buttons in the Range row choose WHICH computed range is output as the mask. They do not switch between three independent spline editors and they do not mean 'edit only this curve.' This is a critical correction to the previous article wording.

Blackmagic describes white pixels in the selected range as fully included, black pixels as excluded and gray pixels as partially included. A gray matte is therefore not automatically dirty or incorrect; it is the expected falloff at a range boundary.

The Spline Display has four main spline points, each with a Bezier handle. The two upper points define the starts of the shadow and highlight ranges, while the two lower points define their ends. The Bezier handles shape the falloff between included and excluded values.

Midtones do not have their own independent boundary controls. They are defined as everything left after the shadow and highlight ranges are applied. Widening Shadows or Highlights therefore reduces Midtones by design rather than through an accidental side effect.

The X and Y fields below the Spline Display belong to the currently selected spline point or Bezier handle and allow precise numeric positioning. They are not the same controls as Center X/Y: Center places the ranges mask/source relative to the output raster, while spline X/Y changes tonal boundaries inside the graph.

Simple and Smooth are not persistent interpolation modes. Blackmagic calls them presets: Simple returns the spline to a straightforward linear-weighted configuration, while Smooth creates a more natural falloff. After applying either preset, the spline points can still be edited manually.

Channel selects the signal from which the ranges are derived. The captured Resolve Inspector verifies Luminance, Red, Green, Blue and Alpha. Luminance is a sensible tonal starting point, but an individual RGB channel can separate a subject much more cleanly; Alpha is useful when source transparency itself carries useful structure.

Level is the global mask-coverage level. Blackmagic's common mask controls define 1.0 as full mask level; lowering it reduces the value of every covered mask pixel. It is not a contrast control and it should not be used in place of editing the spline boundaries.

Soft Edge feathers the resulting mask, while Filter selects the kernel used for that filtering. The captured Inspector offers Box, Bartlett, Multi-box, Gaussian and Fast Gaussian. Build the correct tonal selection first and add Soft Edge afterward so filtering does not hide a bad range definition.

Invert flips the final mask. This differs from Paint Mode = Invert when an external mask is connected: the Invert checkbox reverses the Ranges result as a whole, while the combine mode describes the relationship between two mask streams.

Center X/Y and Fit Input matter when source resolution or aspect differs from mask output. Crop places the source according to Center and clips what falls beyond the mask frame; Stretch fills X and Y independently and can distort; Width/Height scale uniformly to the selected dimension, while Inside/Outside perform proportional fitting relative to the mask frame.

Output Size on the Image tab sets mask-output resolution. The captured Resolve Inspector shows Default, Custom and Source. Source follows the input image size, Default uses the composition/default context, and Custom exposes the common-mask size controls. If the matte is offset or scaled unexpectedly, compare source, mask and target resolutions before compensating elsewhere.

Clipping Mode controls domain-of-definition behavior. The captured Inspector shows None and Frame. It becomes most relevant with Soft Edge and other operations that need samples near or beyond the current DoD; it is not simply an image crop mode.

Paint Mode appears only when Effect Mask is connected. Documented mask-combine modes include Merge, Add, Subtract, Minimum, Maximum, Average, Multiply, Replace, Invert, Copy and Ignore. Multiply is a useful first test when intersecting a tonal range with a spatial Rectangle/Ellipse, but the correct mode depends on the intended mask math.

The most reliable diagnostic view is Ranges.Mask itself in grayscale. If you inspect only the final Glow or ColorCorrector, an overly broad range, a poor channel choice and a bad spline falloff can be mistaken for problems in the downstream effect.

A stable setup order is Image → Channel → output Range → spline/Bezier boundaries → inspect white/gray/black matte → Level/Soft Edge/Filter → optional Effect Mask/Paint Mode → Output Size/Clipping. This keeps tonal selection, mask combination and raster handling as separate decisions.

Ranges does not understand object identity. If skin, sky and a wall share similar values in the chosen Channel, all of them may enter the same range. In that case, constrain the tonal matte spatially through Effect Mask or switch to a keying method better suited to the discrimination problem.

For animated shots, validate the spline matte on multiple frames before keyframing more controls. Narrow ranges on noisy or compressed footage can flicker; widen the falloff, try another Channel or preprocess the analysis source lightly before adding more animation.